Load Bearing Garage Floor over a Basement

   / Load Bearing Garage Floor over a Basement #21  
Joists - 6.5"x8"-30" o.c. 11.5" span

The 11.5' is a typo too.
 
   / Load Bearing Garage Floor over a Basement #22  
Marrt, i've talk to one of our local precast companies last year when we were looking at some property. we could purchace their product in two widths 8' and 10' both in any length to 40' span. If myself or the builder would provide a plan they would modify to fit their product. It wasn't cheap but one of the places we looked at had restictions regarding the "foot print" that a garage or outbuilding could cover and the inspectors coment to me was " I don't care if you have a basement in your garage or put a lower level under your driveway the book says "foot print in square feet not to exeed total of house" if he didn't see it above ground then its not a visable foot print". Kinda made me like an inspector for a change. The precast guys also asked what I was thinking of parking on it and could engineer it for anything from "car" to "dozer with or without the lowboy trailer". The would give dimentions for us to build and they would install the hollow slabs.

.02

Cheer
Tony
 
   / Load Bearing Garage Floor over a Basement #23  
I was shocked too about the steel decking. It is 9/16. But I can't argue with an engineer. I ran it by the steel deck people and they agreed as well. It doesn't act as support for the load. It acts as support for the concrete until the concrete cures, then acts with the concrete as a composite structure. The steel deck eliminates the need for the rebar. 9/16" @ 24-26 guage is what the manufacturer calls for for a 30" span. I'm not shooting from the hip here. I'm getting my info from an engineer and from the manufacturer. It didn't make sense to me either until they explained what everthing was doing.
Yes, the 11.5" is a typo - You are right. It's 11.5'.
I did find some rot directly underneath the main sliding doors (there has not been doors for at least 7 years). So I will have to replace the joists there. Otherwise the rest was in good condition. I'm definetly installing radiant heating in the slab. The PEX tubing was only aprox $240 per 500'. Much less expensive than I thought. I'm really excited about finally restoring this old barn into a workshop. I will start a seperate thread as I start the project.
 
   / Load Bearing Garage Floor over a Basement #24  
So basicly, you'll have a very expensive steel floor with a concrete top on it. Have they quoted you a price for the steel yet, and did you have an oxygen bottle ready or was one provided for you by the engineer and vendor?
I've seen and worked on a lot of steel decks as well as plywood forms for decks, and have yet to see a deck that thick.
Corregated steel decks less than 1/16 thick are self supporting across 6 to 8 feet when concrete is poured on them, and wood forms are usually supported with form jacks till the concrete cures. 9/16 steel on a 30" span is absolutely overkill.
 
   / Load Bearing Garage Floor over a Basement #25  
Franz & Makers_Mark,

<font color="blue"> 9/16" @ 24-26 guage is what the manufacturer calls for for a 30" span </font>

There must be some confusion going on here (as often happens in this form of communication). Is this 9/16" thick plate or some kind of mesh with one of the dimensions being 9/16"? I ask this because you mention 24-26 guage which is about .024 - .0217" thick (galvanized)

9/16" steel plate weighs 23 pounds per square foot! You certaintly woudn't need any concrete on top of it to support a load.
 
   / Load Bearing Garage Floor over a Basement #26  
I used the steel deck and it is a heavy gauge sheet metal
w/ 1" hi steps about 2.5" apart.
This stuff was HARD to cut w/ tin snips, used cutoff wheel.
I wonder if this has 9/16" high steps?
The higher the steps the more strength, my pour was 5'
span.
If u heat the floor, dou want heat under the floor also?
If u only want heat to go up put 2" blue board under
the concrete and the pex on top.
U could always insulate under the steel deck too.
 
   / Load Bearing Garage Floor over a Basement #27  
I've attached a shot of the deck spec for anyone who is interested. Should clear things up. I even said to the engineer that I had no problem going to a heavier guage and taller "wave" pattern but said it wasn't neccessary - go figure /forums/images/graemlins/confused.gif
 

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   / Load Bearing Garage Floor over a Basement #28  
Thanks for your advice. I was looking to heat both spaces. I will probably heat the lower space with a wood burning stove or something. Question - what happens if the PEX goes bad if it's imbedded in the concrete?
 
   / Load Bearing Garage Floor over a Basement #29  
<font color="blue">Hoeman00 - my pour was 5' span</font>

What did you lay the steel over. I'm interested to know more details? Joist height, slab thickness, etc.
 
   / Load Bearing Garage Floor over a Basement #30  
Mark,

A picture is worth a thousand words. clears things up for me! Thanks!
 
 
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